On board electronic control units (ECU) can control all aspects of an automobile's operation such as the fuel system, ignition system, traction control system and air conditioning and heating systems. A typical automobile may contain dozens of ECUs. Because safety and reliability standards for automotive electronics have become increasingly more stringent, the ability to quickly test newly manufactured electronic units and debug failing units has become increasingly more important.
Automotive ECU modules commonly consist of a microcontroller or microprocessor and other circuits such as memory and interface circuitry mounted on a printed circuit board (PCB) and interfaced with a single connector that provides power and signal interfaces. If a component within the ECU module fails, pinpointing the cause of the failure generally involves physically opening the module and analyzing the failure by probing the PCB, supplying test signals, and de-soldering individual components on which to perform a failure analysis.
One complicating factor in performing test and debug on an ECU module is that the testing functions on individual components are often only accessible via dedicated pins that are tied to supply and ground during normal operation. Because test interfaces are unavailable at the module level, the possibility of quickly performing a comprehensive debug and/or failure analysis in the field is very limited.
In the field of automotive electronics, what are needed are systems and methods of quickly testing and performing failure analysis on modules without disassembling the module.